SPACEX LAUNCH If all goes according to plan, tomorrow, Saturday, May 19th, SpaceX will become the first commercial space flight company in history to head for the International Space Station. You can watch online, live, at SpaceX.com starting at 1:15 AM Pacific / 4:15 AM Eastern / 08:15 UTC. You can also follow SpaceX founder and CEO @elonmusk on Twitter. He'll live-tweet from mission control during launch.

Galileo Meets Ganymede [USGS Astrogeology Science Center/Wheaton/NASA/JPL-Caltech] Monday, June 27, 2016: Twenty years ago today, on June 27, 1996, the Galileo spacecraft (the first space probe to orbit Jupiter) made its first close flyby of the moon Ganymede. This image was created in 2014 using data from Galileo, as well as the Voyager probes, and shows the geologic detail of the moon’s surface. — Calla Cofield